I have accidentally formatted my SATA hard drive (4TB, ext4 file system), which is used as a detachable hard drive in docking station. I was re-installing Linux Mint OS, while the hard drive was still inside the docking station, and instead of installing it within the default internal SSD drive, it started installing within the SATA 4TB HDD. As soon as I realised this, I immediately took it out from the docking station. Unfortunately, all my data (approx. 2TB) are formatted, showing an empty 4TB space. However, it didn't seem to overwrite anything, except for a 34GB partition that was created for the OS system files, which is mostly empty.

Most of the data in the drive consisted of trajectory files from simulations having a non-standard extension .xtc or .trr. These files were generated/written in binary/ASCII. Is there any way either of TestDisk or PhotoRec could recover/recognise these? It would be very helpful if you could advise me on this. I wish I could attach a sample file for your perusal, but the attachment interface does not allow non-standard extensions.